That was because the biggest rage-frothing complaint about sharding in these forums, was that people just disappear any time they move between areas. So they changed the system so that people would be visible (sans re-grouping) the entire time no matter where they went.
They changed the implementation because the community demanded it. They only have so much leeway because their corporate overlords need a smooth launch, but they’re trying to fix the problems by taking our complaints and adjusting the solution.
You’re literally complaining that they moved towards what we wanted.